1. Field of the Invention
This invention pertains to lubricants having incorporated therein dispersant oil soluble polyisobutenyl butyrolactones and lactams derived therefrom.
Lubricants used in the crankcase of internal combustion engines, gears and power transmitting units become contaminated by foreign particles. Deposition of such particles is known to interfere with proper operation of such mechanisms and accordingly the lubricants must contain dispersant additives which keep the particles highly dispersed in a condition unfavorable for deposition on metals.
2. Discussion of the Prior Art
The relevant prior art includes U.S. Pat. Nos. 3,200,075; 3,272,746; 3,341,542; and 3,775,431.
Of these, the first teaches that certain lactone amides are useful as lubricating oil detergents. U.S. Pat. No. 3,248,187 discloses alkenyl dicarboxylic acid lactones useful as rust inhibitors. U.S. Pat. No. 3,341,542 discloses acylated nitrogenous compounds as dispersing agents in lubricants and which are obtained by condensing a hydroxyalkyl-substituted alkylene amine with an acid. U.S. Pat. No. 3,775,431 reports the synthesis of butyrolactams by reacting a gamma lactone with ammonia or a primary amine over a zeolite.
In the chemical literature, Bloomfield et al, in J. Org. Chem. 32 (12), 3919-24 (1967) disclose the reduction of cyclic anhydrides to lactones or diols with LiAlH.sub.4. Bailey et al in J. Org. Chem. 1970, 35 (10), 3574-6 show the reduction of cyclic anhydride with NaBH.sub.4. Kayser et al published in Can. J. Chem. 1978, 56 (11), 1524-32 a paper discussing factors affecting the regioselectivity of attack on the carbonyl group of cyclic anhydrides by metal hydrides. To date, however, research on the reduction of compounds having possible utility as lubricant additives has not been extended.
None of the above in any way suggests the present invention.